git/unpack-trees.c
Linus Torvalds 6fda5e5180 Initialize tree descriptors with a helper function rather than by hand.
This removes slightly more lines than it adds, but the real reason for
doing this is that future optimizations will require more setup of the
tree descriptor, and so we want to do it in one place.

Also renamed the "desc.buf" field to "desc.buffer" just to trigger
compiler errors for old-style manual initializations, making sure I
didn't miss anything.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-21 10:21:57 -07:00

811 lines
18 KiB
C

#include "cache.h"
#include "dir.h"
#include "tree.h"
#include "tree-walk.h"
#include "cache-tree.h"
#include "unpack-trees.h"
#define DBRT_DEBUG 1
struct tree_entry_list {
struct tree_entry_list *next;
unsigned directory : 1;
unsigned executable : 1;
unsigned symlink : 1;
unsigned int mode;
const char *name;
const unsigned char *sha1;
};
static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
{
struct tree_desc desc;
struct name_entry one;
struct tree_entry_list *ret = NULL;
struct tree_entry_list **list_p = &ret;
if (!tree->object.parsed)
parse_tree(tree);
init_tree_desc(&desc, tree->buffer, tree->size);
while (tree_entry(&desc, &one)) {
struct tree_entry_list *entry;
entry = xmalloc(sizeof(struct tree_entry_list));
entry->name = one.path;
entry->sha1 = one.sha1;
entry->mode = one.mode;
entry->directory = S_ISDIR(one.mode) != 0;
entry->executable = (one.mode & S_IXUSR) != 0;
entry->symlink = S_ISLNK(one.mode) != 0;
entry->next = NULL;
*list_p = entry;
list_p = &entry->next;
}
return ret;
}
static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
{
int len1 = strlen(name1);
int len2 = strlen(name2);
int len = len1 < len2 ? len1 : len2;
int ret = memcmp(name1, name2, len);
unsigned char c1, c2;
if (ret)
return ret;
c1 = name1[len];
c2 = name2[len];
if (!c1 && dir1)
c1 = '/';
if (!c2 && dir2)
c2 = '/';
ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
if (c1 && c2 && !ret)
ret = len1 - len2;
return ret;
}
static int unpack_trees_rec(struct tree_entry_list **posns, int len,
const char *base, struct unpack_trees_options *o,
int *indpos,
struct tree_entry_list *df_conflict_list)
{
int baselen = strlen(base);
int src_size = len + 1;
int i_stk = i_stk;
int retval = 0;
if (o->dir)
i_stk = push_exclude_per_directory(o->dir, base, strlen(base));
do {
int i;
const char *first;
int firstdir = 0;
int pathlen;
unsigned ce_size;
struct tree_entry_list **subposns;
struct cache_entry **src;
int any_files = 0;
int any_dirs = 0;
char *cache_name;
int ce_stage;
/* Find the first name in the input. */
first = NULL;
cache_name = NULL;
/* Check the cache */
if (o->merge && *indpos < active_nr) {
/* This is a bit tricky: */
/* If the index has a subdirectory (with
* contents) as the first name, it'll get a
* filename like "foo/bar". But that's after
* "foo", so the entry in trees will get
* handled first, at which point we'll go into
* "foo", and deal with "bar" from the index,
* because the base will be "foo/". The only
* way we can actually have "foo/bar" first of
* all the things is if the trees don't
* contain "foo" at all, in which case we'll
* handle "foo/bar" without going into the
* directory, but that's fine (and will return
* an error anyway, with the added unknown
* file case.
*/
cache_name = active_cache[*indpos]->name;
if (strlen(cache_name) > baselen &&
!memcmp(cache_name, base, baselen)) {
cache_name += baselen;
first = cache_name;
} else {
cache_name = NULL;
}
}
#if DBRT_DEBUG > 1
if (first)
printf("index %s\n", first);
#endif
for (i = 0; i < len; i++) {
if (!posns[i] || posns[i] == df_conflict_list)
continue;
#if DBRT_DEBUG > 1
printf("%d %s\n", i + 1, posns[i]->name);
#endif
if (!first || entcmp(first, firstdir,
posns[i]->name,
posns[i]->directory) > 0) {
first = posns[i]->name;
firstdir = posns[i]->directory;
}
}
/* No name means we're done */
if (!first)
goto leave_directory;
pathlen = strlen(first);
ce_size = cache_entry_size(baselen + pathlen);
src = xcalloc(src_size, sizeof(struct cache_entry *));
subposns = xcalloc(len, sizeof(struct tree_list_entry *));
if (cache_name && !strcmp(cache_name, first)) {
any_files = 1;
src[0] = active_cache[*indpos];
remove_cache_entry_at(*indpos);
}
for (i = 0; i < len; i++) {
struct cache_entry *ce;
if (!posns[i] ||
(posns[i] != df_conflict_list &&
strcmp(first, posns[i]->name))) {
continue;
}
if (posns[i] == df_conflict_list) {
src[i + o->merge] = o->df_conflict_entry;
continue;
}
if (posns[i]->directory) {
struct tree *tree = lookup_tree(posns[i]->sha1);
any_dirs = 1;
parse_tree(tree);
subposns[i] = create_tree_entry_list(tree);
posns[i] = posns[i]->next;
src[i + o->merge] = o->df_conflict_entry;
continue;
}
if (!o->merge)
ce_stage = 0;
else if (i + 1 < o->head_idx)
ce_stage = 1;
else if (i + 1 > o->head_idx)
ce_stage = 3;
else
ce_stage = 2;
ce = xcalloc(1, ce_size);
ce->ce_mode = create_ce_mode(posns[i]->mode);
ce->ce_flags = create_ce_flags(baselen + pathlen,
ce_stage);
memcpy(ce->name, base, baselen);
memcpy(ce->name + baselen, first, pathlen + 1);
any_files = 1;
hashcpy(ce->sha1, posns[i]->sha1);
src[i + o->merge] = ce;
subposns[i] = df_conflict_list;
posns[i] = posns[i]->next;
}
if (any_files) {
if (o->merge) {
int ret;
#if DBRT_DEBUG > 1
printf("%s:\n", first);
for (i = 0; i < src_size; i++) {
printf(" %d ", i);
if (src[i])
printf("%s\n", sha1_to_hex(src[i]->sha1));
else
printf("\n");
}
#endif
ret = o->fn(src, o);
#if DBRT_DEBUG > 1
printf("Added %d entries\n", ret);
#endif
*indpos += ret;
} else {
for (i = 0; i < src_size; i++) {
if (src[i]) {
add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
}
}
}
}
if (any_dirs) {
char *newbase = xmalloc(baselen + 2 + pathlen);
memcpy(newbase, base, baselen);
memcpy(newbase + baselen, first, pathlen);
newbase[baselen + pathlen] = '/';
newbase[baselen + pathlen + 1] = '\0';
if (unpack_trees_rec(subposns, len, newbase, o,
indpos, df_conflict_list)) {
retval = -1;
goto leave_directory;
}
free(newbase);
}
free(subposns);
free(src);
} while (1);
leave_directory:
if (o->dir)
pop_exclude_per_directory(o->dir, i_stk);
return retval;
}
/* Unlink the last component and attempt to remove leading
* directories, in case this unlink is the removal of the
* last entry in the directory -- empty directories are removed.
*/
static void unlink_entry(char *name)
{
char *cp, *prev;
if (unlink(name))
return;
prev = NULL;
while (1) {
int status;
cp = strrchr(name, '/');
if (prev)
*prev = '/';
if (!cp)
break;
*cp = 0;
status = rmdir(name);
if (status) {
*cp = '/';
break;
}
prev = cp;
}
}
static volatile sig_atomic_t progress_update;
static void progress_interval(int signum)
{
progress_update = 1;
}
static void setup_progress_signal(void)
{
struct sigaction sa;
struct itimerval v;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = progress_interval;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
sigaction(SIGALRM, &sa, NULL);
v.it_interval.tv_sec = 1;
v.it_interval.tv_usec = 0;
v.it_value = v.it_interval;
setitimer(ITIMER_REAL, &v, NULL);
}
static struct checkout state;
static void check_updates(struct cache_entry **src, int nr,
struct unpack_trees_options *o)
{
unsigned short mask = htons(CE_UPDATE);
unsigned last_percent = 200, cnt = 0, total = 0;
if (o->update && o->verbose_update) {
for (total = cnt = 0; cnt < nr; cnt++) {
struct cache_entry *ce = src[cnt];
if (!ce->ce_mode || ce->ce_flags & mask)
total++;
}
/* Don't bother doing this for very small updates */
if (total < 250)
total = 0;
if (total) {
fprintf(stderr, "Checking files out...\n");
setup_progress_signal();
progress_update = 1;
}
cnt = 0;
}
while (nr--) {
struct cache_entry *ce = *src++;
if (total) {
if (!ce->ce_mode || ce->ce_flags & mask) {
unsigned percent;
cnt++;
percent = (cnt * 100) / total;
if (percent != last_percent ||
progress_update) {
fprintf(stderr, "%4u%% (%u/%u) done\r",
percent, cnt, total);
last_percent = percent;
progress_update = 0;
}
}
}
if (!ce->ce_mode) {
if (o->update)
unlink_entry(ce->name);
continue;
}
if (ce->ce_flags & mask) {
ce->ce_flags &= ~mask;
if (o->update)
checkout_entry(ce, &state, NULL);
}
}
if (total) {
signal(SIGALRM, SIG_IGN);
fputc('\n', stderr);
}
}
int unpack_trees(struct object_list *trees, struct unpack_trees_options *o)
{
int indpos = 0;
unsigned len = object_list_length(trees);
struct tree_entry_list **posns;
int i;
struct object_list *posn = trees;
struct tree_entry_list df_conflict_list;
static struct cache_entry *dfc;
memset(&df_conflict_list, 0, sizeof(df_conflict_list));
df_conflict_list.next = &df_conflict_list;
memset(&state, 0, sizeof(state));
state.base_dir = "";
state.force = 1;
state.quiet = 1;
state.refresh_cache = 1;
o->merge_size = len;
if (!dfc)
dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
o->df_conflict_entry = dfc;
if (len) {
posns = xmalloc(len * sizeof(struct tree_entry_list *));
for (i = 0; i < len; i++) {
posns[i] = create_tree_entry_list((struct tree *) posn->item);
posn = posn->next;
}
if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
o, &indpos, &df_conflict_list))
return -1;
}
if (o->trivial_merges_only && o->nontrivial_merge)
die("Merge requires file-level merging");
check_updates(active_cache, active_nr, o);
return 0;
}
/* Here come the merge functions */
static void reject_merge(struct cache_entry *ce)
{
die("Entry '%s' would be overwritten by merge. Cannot merge.",
ce->name);
}
static int same(struct cache_entry *a, struct cache_entry *b)
{
if (!!a != !!b)
return 0;
if (!a && !b)
return 1;
return a->ce_mode == b->ce_mode &&
!hashcmp(a->sha1, b->sha1);
}
/*
* When a CE gets turned into an unmerged entry, we
* want it to be up-to-date
*/
static void verify_uptodate(struct cache_entry *ce,
struct unpack_trees_options *o)
{
struct stat st;
if (o->index_only || o->reset)
return;
if (!lstat(ce->name, &st)) {
unsigned changed = ce_match_stat(ce, &st, 1);
if (!changed)
return;
errno = 0;
}
if (o->reset) {
ce->ce_flags |= htons(CE_UPDATE);
return;
}
if (errno == ENOENT)
return;
die("Entry '%s' not uptodate. Cannot merge.", ce->name);
}
static void invalidate_ce_path(struct cache_entry *ce)
{
if (ce)
cache_tree_invalidate_path(active_cache_tree, ce->name);
}
/*
* We do not want to remove or overwrite a working tree file that
* is not tracked, unless it is ignored.
*/
static void verify_absent(const char *path, const char *action,
struct unpack_trees_options *o)
{
struct stat st;
if (o->index_only || o->reset || !o->update)
return;
if (!lstat(path, &st) && !(o->dir && excluded(o->dir, path)))
die("Untracked working tree file '%s' "
"would be %s by merge.", path, action);
}
static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
struct unpack_trees_options *o)
{
merge->ce_flags |= htons(CE_UPDATE);
if (old) {
/*
* See if we can re-use the old CE directly?
* That way we get the uptodate stat info.
*
* This also removes the UPDATE flag on
* a match.
*/
if (same(old, merge)) {
*merge = *old;
} else {
verify_uptodate(old, o);
invalidate_ce_path(old);
}
}
else {
verify_absent(merge->name, "overwritten", o);
invalidate_ce_path(merge);
}
merge->ce_flags &= ~htons(CE_STAGEMASK);
add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
return 1;
}
static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
struct unpack_trees_options *o)
{
if (old)
verify_uptodate(old, o);
else
verify_absent(ce->name, "removed", o);
ce->ce_mode = 0;
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
invalidate_ce_path(ce);
return 1;
}
static int keep_entry(struct cache_entry *ce)
{
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
return 1;
}
#if DBRT_DEBUG
static void show_stage_entry(FILE *o,
const char *label, const struct cache_entry *ce)
{
if (!ce)
fprintf(o, "%s (missing)\n", label);
else
fprintf(o, "%s%06o %s %d\t%s\n",
label,
ntohl(ce->ce_mode),
sha1_to_hex(ce->sha1),
ce_stage(ce),
ce->name);
}
#endif
int threeway_merge(struct cache_entry **stages,
struct unpack_trees_options *o)
{
struct cache_entry *index;
struct cache_entry *head;
struct cache_entry *remote = stages[o->head_idx + 1];
int count;
int head_match = 0;
int remote_match = 0;
const char *path = NULL;
int df_conflict_head = 0;
int df_conflict_remote = 0;
int any_anc_missing = 0;
int no_anc_exists = 1;
int i;
for (i = 1; i < o->head_idx; i++) {
if (!stages[i])
any_anc_missing = 1;
else {
if (!path)
path = stages[i]->name;
no_anc_exists = 0;
}
}
index = stages[0];
head = stages[o->head_idx];
if (head == o->df_conflict_entry) {
df_conflict_head = 1;
head = NULL;
}
if (remote == o->df_conflict_entry) {
df_conflict_remote = 1;
remote = NULL;
}
if (!path && index)
path = index->name;
if (!path && head)
path = head->name;
if (!path && remote)
path = remote->name;
/* First, if there's a #16 situation, note that to prevent #13
* and #14.
*/
if (!same(remote, head)) {
for (i = 1; i < o->head_idx; i++) {
if (same(stages[i], head)) {
head_match = i;
}
if (same(stages[i], remote)) {
remote_match = i;
}
}
}
/* We start with cases where the index is allowed to match
* something other than the head: #14(ALT) and #2ALT, where it
* is permitted to match the result instead.
*/
/* #14, #14ALT, #2ALT */
if (remote && !df_conflict_head && head_match && !remote_match) {
if (index && !same(index, remote) && !same(index, head))
reject_merge(index);
return merged_entry(remote, index, o);
}
/*
* If we have an entry in the index cache, then we want to
* make sure that it matches head.
*/
if (index && !same(index, head)) {
reject_merge(index);
}
if (head) {
/* #5ALT, #15 */
if (same(head, remote))
return merged_entry(head, index, o);
/* #13, #3ALT */
if (!df_conflict_remote && remote_match && !head_match)
return merged_entry(head, index, o);
}
/* #1 */
if (!head && !remote && any_anc_missing)
return 0;
/* Under the new "aggressive" rule, we resolve mostly trivial
* cases that we historically had git-merge-one-file resolve.
*/
if (o->aggressive) {
int head_deleted = !head && !df_conflict_head;
int remote_deleted = !remote && !df_conflict_remote;
/*
* Deleted in both.
* Deleted in one and unchanged in the other.
*/
if ((head_deleted && remote_deleted) ||
(head_deleted && remote && remote_match) ||
(remote_deleted && head && head_match)) {
if (index)
return deleted_entry(index, index, o);
else if (path && !head_deleted)
verify_absent(path, "removed", o);
return 0;
}
/*
* Added in both, identically.
*/
if (no_anc_exists && head && remote && same(head, remote))
return merged_entry(head, index, o);
}
/* Below are "no merge" cases, which require that the index be
* up-to-date to avoid the files getting overwritten with
* conflict resolution files.
*/
if (index) {
verify_uptodate(index, o);
}
o->nontrivial_merge = 1;
/* #2, #3, #4, #6, #7, #9, #11. */
count = 0;
if (!head_match || !remote_match) {
for (i = 1; i < o->head_idx; i++) {
if (stages[i]) {
keep_entry(stages[i]);
count++;
break;
}
}
}
#if DBRT_DEBUG
else {
fprintf(stderr, "read-tree: warning #16 detected\n");
show_stage_entry(stderr, "head ", stages[head_match]);
show_stage_entry(stderr, "remote ", stages[remote_match]);
}
#endif
if (head) { count += keep_entry(head); }
if (remote) { count += keep_entry(remote); }
return count;
}
/*
* Two-way merge.
*
* The rule is to "carry forward" what is in the index without losing
* information across a "fast forward", favoring a successful merge
* over a merge failure when it makes sense. For details of the
* "carry forward" rule, please see <Documentation/git-read-tree.txt>.
*
*/
int twoway_merge(struct cache_entry **src,
struct unpack_trees_options *o)
{
struct cache_entry *current = src[0];
struct cache_entry *oldtree = src[1], *newtree = src[2];
if (o->merge_size != 2)
return error("Cannot do a twoway merge of %d trees",
o->merge_size);
if (current) {
if ((!oldtree && !newtree) || /* 4 and 5 */
(!oldtree && newtree &&
same(current, newtree)) || /* 6 and 7 */
(oldtree && newtree &&
same(oldtree, newtree)) || /* 14 and 15 */
(oldtree && newtree &&
!same(oldtree, newtree) && /* 18 and 19*/
same(current, newtree))) {
return keep_entry(current);
}
else if (oldtree && !newtree && same(current, oldtree)) {
/* 10 or 11 */
return deleted_entry(oldtree, current, o);
}
else if (oldtree && newtree &&
same(current, oldtree) && !same(current, newtree)) {
/* 20 or 21 */
return merged_entry(newtree, current, o);
}
else {
/* all other failures */
if (oldtree)
reject_merge(oldtree);
if (current)
reject_merge(current);
if (newtree)
reject_merge(newtree);
return -1;
}
}
else if (newtree)
return merged_entry(newtree, current, o);
else
return deleted_entry(oldtree, current, o);
}
/*
* Bind merge.
*
* Keep the index entries at stage0, collapse stage1 but make sure
* stage0 does not have anything there.
*/
int bind_merge(struct cache_entry **src,
struct unpack_trees_options *o)
{
struct cache_entry *old = src[0];
struct cache_entry *a = src[1];
if (o->merge_size != 1)
return error("Cannot do a bind merge of %d trees\n",
o->merge_size);
if (a && old)
die("Entry '%s' overlaps. Cannot bind.", a->name);
if (!a)
return keep_entry(old);
else
return merged_entry(a, NULL, o);
}
/*
* One-way merge.
*
* The rule is:
* - take the stat information from stage0, take the data from stage1
*/
int oneway_merge(struct cache_entry **src,
struct unpack_trees_options *o)
{
struct cache_entry *old = src[0];
struct cache_entry *a = src[1];
if (o->merge_size != 1)
return error("Cannot do a oneway merge of %d trees",
o->merge_size);
if (!a)
return deleted_entry(old, old, o);
if (old && same(old, a)) {
if (o->reset) {
struct stat st;
if (lstat(old->name, &st) ||
ce_match_stat(old, &st, 1))
old->ce_flags |= htons(CE_UPDATE);
}
return keep_entry(old);
}
return merged_entry(a, old, o);
}